Estimated/Expected sizes in v$SQL_WORKAREA / _ACTIVE Views
From: Hemant K Chitale <hkchital_at_singnet.com.sg>
Date: Sun, 11 Apr 2010 23:37:29 +0800
Message-Id: <201004111537.o3BFbY81015404_at_smtp14.singnet.com.sg>
Date: Sun, 11 Apr 2010 23:37:29 +0800
Message-Id: <201004111537.o3BFbY81015404_at_smtp14.singnet.com.sg>
Does anyone have a test case to identify how Oracle comes up with ESTIMATED_OPTIMAL_SIZE / ESTIMATED_ONEPASS_SIZE / EXPECTED_SIZE in V$SQL_WORKAREA and V$SQL_WORKAREA_ACTIVE.
Trying to fool the optimizer with fake Table statistics doesn't seem to change it's estimate (however, I can't fake the Table Segment Size !). (Tests in 10.2.0.4 on Linux).
I wonder how it computes the Estimated/Expected sizes.
Hemant K Chitale
http://hemantoracledba.blogspot.com
-- http://www.freelists.org/webpage/oracle-lReceived on Sun Apr 11 2010 - 10:37:29 CDT